Alterations of gut microbiota and metabolome in early chronic kidney disease patients complicated with hyperuricemia

OBJECT: This study aims to investigate the changes in gut microbiota and metabolism of patients with chronic kidney disease (CKD) stage 1–2, as well as the potential impact of hyperuricemia (HUA) on these factors in CKD stage 1–2 patients. METHODS: In this study, fecal samples were collected from CKD stage 1–2 without HUA patients (CKD-N group), CKD stage 1–2 with HUA patients (CKD-H group), and healthy people controls (HCs group). The samples were then subjected to the microbiome (16S rRNA gene sequencing) and metabolome (liquid chromatography-tandem mass spectrometry) analyses. The multi-omics datasets were analyzed individually and integrated for combined analysis using various bioinformatics approaches. RESULTS: Gut microbial dysbiosis was found in CKD-N and CKD-H patients. At the phylum level, compared to HCs group, Bacteroidetes decreased but Proteobacteria increased in CKD-H group significantly. Fusobacteria in CKD-N group was significantly lower than HCs group. At genus level, [Eubacterium]_ventriosum_group, Fusobacterium, Agathobacter, Parabacteroides, and Roseburia significantly changed in CKD groups. [Ruminococcus]_gnavus_group was significantly lower in CKD-H group than CKD-N group. Moreover, the fecal metabolome of CKD-N and CKD-H altered significantly. d-glutamine and d-glutamate metabolism, arginine and proline metabolism, histidine metabolism, and lysine biosynthesis were down-regulated in the CKD-N group. Phenylalanine metabolism, arginine and proline metabolism, purine metabolism, and beta-alanine metabolism were up-regulated in the CKD-H group. There was a significant difference between the two CKD groups in phenylalanine metabolism. The abundance change of [Ruminococcus]_gnavus_group, [Eubacterium]_ventriosum_group, UCG-002, Alistipes, and Bifidobacterium had a close correlation with differential metabolites. CONCLUSION: The gut microbiota and metabolic status undergo significant changes in CKD patients compared to healthy people. Additionally, HUA has been found to impact the gut microbiota of CKD patients, as well as their metabolism. The close association between gut microbiota and metabolites suggests that the former plays a crucial role in metabolism.